smart_tunnel_edge/protocol/switchRelay/service.go

package switchRelay

import (
	"encoding/hex"
	"github.com/valyala/bytebufferpool"
)

func (x DataPack) GetSwitchRelayCommand() *bytebufferpool.ByteBuffer {
	buf := bytebufferpool.Get()
	x.Function = 0x05
	decodeAddress, _ := hex.DecodeString(x.Address)
	buf.Write(decodeAddress)
	buf.WriteByte(x.Function)
	buf.Write([]byte{0x00, byte(x.Way - 1)})
	if x.Command == 1 {
		buf.Write([]byte{0xFF, 0x00})
	} else {
		buf.Write([]byte{0x00, 0x00})
	}

	x.Crc = calculateCRC16Modbus(buf.Bytes())
	buf.Write([]byte{byte(x.Crc & 0xFF), byte(x.Crc >> 8)})
	return buf
}

func (x MultiLoopDataPack) GetControlMuchSwitchRelayCommand() *bytebufferpool.ByteBuffer {
	buf := bytebufferpool.Get()
	x.Function = 0x10
	decodeAddress, _ := hex.DecodeString(x.Address)
	buf.Write(decodeAddress)
	buf.WriteByte(x.Function)
	if x.TurnOff == 1 { //控制多路打开
		buf.Write([]byte{0x04, 0x1A, 0x00, 0x02, 0x04, 0x00})
	} else if x.TurnOff == 0 { //控制多路关闭
		buf.Write([]byte{0x04, 0x1C, 0x00, 0x02, 0x04, 0x00})
	} else { //控制多路取反
		buf.Write([]byte{0x04, 0x1E, 0x00, 0x02, 0x04, 0x00})
	}
	buf.Write(generateHexSwitchState(x.State))
	x.Command = []byte{0x00, 0x00}
	buf.Write(x.Command)
	x.Crc = calculateCRC16Modbus(buf.Bytes())
	buf.Write([]byte{byte(x.Crc & 0xFF), byte(x.Crc >> 8)})
	return buf
}

func calculateCRC16Modbus(data []byte) uint16 {
	var crc uint16 = 0xFFFF // CRC-16 初始化值
	for _, byteVal := range data {
		crc ^= uint16(byteVal) // 对字节进行异或操作
		for i := 0; i < 8; i++ {
			if crc&0x0001 != 0 {
				crc >>= 1
				crc ^= 0xA001 // 多项式 0xA001
			} else {
				crc >>= 1
			}
		}
	}
	return crc
}

func generateHexSwitchState(switches []int) []byte {
	var state int

	// 遍历切片，设置对应位置的开关为 1
	for _, s := range switches {
		state |= 1 << (s - 1) // 设置第s位为1，s从1开始
	}

	// 返回字节切片，使用 []byte{} 来包裹十六进制值
	return []byte{byte(state)}
}